Magnetic memory alloy with large strain and preparation method thereof

A technology of memory alloy and large strain, which is applied in the manufacture of inductors/transformers/magnets, magnetic materials, magnetic objects, etc. It can solve the problem that magnetic shape memory alloys have not made obvious breakthroughs, hinder the application and promotion of alloys, and have unsatisfactory repeatability and other issues, to achieve the effect of broadening the scope of industrial applications, excellent mechanical properties, and large magnetic strain

Active Publication Date: 2018-12-28
HOHAI UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, after decades of development, magnetic shape memory alloys still have defects such as serious single crystal segregation, poor polycrystalline toughness, small strain, unsatisfactory repeatability and low Curie point, especially magnetic shape memory alloys. There has been no significant breakthrough in the amount of strain, which greatly hinders the application and promotion of this type of alloy. Therefore, it is expected to develop a alloy with good mechanical properties, a martensitic transformation temperature near room temperature, and a large strain capacity. Novel magnetic control shape memory alloy to accelerate its application and promotion in industrial applications

Method used

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  • Magnetic memory alloy with large strain and preparation method thereof
  • Magnetic memory alloy with large strain and preparation method thereof
  • Magnetic memory alloy with large strain and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Prepare 500g composition as Co 21.6 Ni 36.7 al 41.0 La 0.7 A magnetic memory alloy with large strain, its preparation method is as follows:

[0027] S1. Ingredients: Weigh Co, Ni, Al, La with a purity of 99.99% respectively;

[0028] S2. Melting: Put the prepared raw materials in a crucible for vacuum melting, the melting conditions are: a.5×10 -2 The low vacuum state of MPa; b. the smelting temperature is 1450 ℃; c. the smelting process adopts magnetic stirring; d. the smelting time is 335s (according to the formula t=K×(M -1 / 2 ) to obtain, where the element coefficient K is 15s g -1 / 2 , M is 500g);

[0029] S3. Magnetic field heat treatment: The alloy ingot obtained by the above vacuum melting is subjected to vacuum magnetic field heat treatment, the treatment conditions are: temperature 655°C; time: 6 hours; vacuum degree: 1×10 -3 MPa; Applied magnetic field strength: 5×10 5 A·m -1 ; Magnetic field rise rate: 500A·m -1 ·s -1 ;

[0030] S4. Cooling: then c...

Embodiment 2

[0033] Prepare 800g composition as Co 21.7 Ni 32.5 al 39.1 La 6.7 A magnetic memory alloy with large strain, its preparation method is as follows:

[0034] S1. Ingredients: Weigh Co, Ni, Al, La with a purity of 99.99% respectively;

[0035] S2. Melting: Put the prepared raw materials in a crucible for vacuum melting, the melting conditions are: a.8×10 -2 The low vacuum state of MPa; b. melting temperature is 1480 ℃; c. melting process adopts magnetic stirring; d. melting time is 368s (according to formula t=K×(M -1 / 2 ) to obtain, where the element coefficient K is 13s g -1 / 2 , M is 800g);

[0036] S3. Magnetic field heat treatment: The alloy ingot obtained by the above vacuum melting is subjected to vacuum magnetic field heat treatment, the treatment conditions are: temperature 670°C; time: 5.5 hours; vacuum degree: 7×10 -2 MPa; Applied magnetic field strength: 6×10 5 A·m -1 ; Magnetic field rise rate: 500A·m -1 ·s -1 ;

[0037] S4. Cooling: followed by furnace coo...

Embodiment 3

[0040] Prepare 400g composition as Co 22.5 Ni 35.3 al 39.1 La 3.1 A magnetic memory alloy with large strain, its preparation method is as follows:

[0041] S1. Ingredients: Weigh Co, Ni, Al, La with a purity of 99.99% respectively;

[0042] S2. Melting: Put the prepared raw materials in a crucible for vacuum melting, and the melting conditions are: a.9×10 -2 The low vacuum state of MPa; b. the smelting temperature is 1500 ℃; c. the smelting process adopts magnetic stirring; d. the smelting time is 240s (according to the formula t=K×(M -1 / 2 ) to obtain, where the element coefficient K is 12s g -1 / 2 , M is 400g);

[0043] S3. Magnetic field heat treatment: The alloy ingot obtained by the above vacuum melting is subjected to vacuum magnetic field heat treatment, the treatment conditions are: temperature 680°C; time: 5 hours; vacuum degree: 9×10 -2 MPa; Applied magnetic field strength: 1×10 6 A·m -1 ; Magnetic field rise rate: 500A·m -1 ·s -1 ;

[0044] S4. Cooling: th...

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PUM

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Abstract

The invention provides a magnetic memory alloy with large strain and a preparation method thereof and belongs to the field of shape memory alloys. The alloy has the capacity of generating high magnetic strain under control of an external magnetic field at the room temperature condition, and is a magnetic control shape memory alloy capable of driving martensite twin grain boundary migration and reverse migration through changes of the external magnetic field so as to generate recoverable strain at the room temperature condition. The chemical formula of the alloy is CoxNiyAlzLaj, wherein x is larger than or equal to 21.6 and smaller than or equal to 27.9, y is larger than or equal to 32.1 and smaller than or equal to 36.7, z is larger than or equal to 38.2 and smaller than or equal to 54.6,j is larger than or equal to 0.7 and smaller than or equal to 6.7, the sum of x, y, z and j is 100, and x, y, z and j represent Mole percentages. Compared with an existing material, by forming an ultrafine Al3La metal intermediate phase in a matrix of the memory alloy, the alloy has a wide magnetic strain temperature range, high magnetic strain capacity and good mechanical properties, and has important application to the field of high-precision drivers, actuators and the like used at the room temperature condition.

Description

technical field [0001] The invention belongs to the field of magnetic shape memory alloys, in particular to a magnetic memory alloy with large strain and a preparation method thereof. Background technique [0002] The shape memory effect of traditional shape memory alloys mainly comes from the martensitic phase transformation of the alloy under the drive of external temperature or stress. This shape memory effect is characterized by high driving force and large strain. However, on the other hand, the driving conditions of traditional shape memory alloys require a long start-up time, which also causes the corresponding frequency of this type of alloy to be low and cannot respond quickly to strain. [0003] Based on the application defects of traditional shape memory alloys, magnetic shape memory alloys with fast response frequency have received more and more attention. Magnetic shape memory alloy is a kind of shape memory material with thermoelastic martensitic transformati...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C1/02C22C30/00C22F1/10H01F1/057H01F41/02
CPCC22C1/023C22C19/03C22C30/00C22F1/006C22F1/10H01F1/057H01F41/0253
Inventor 刘欢巨佳刘壮张思斌许永祥张慧王策黄河
Owner HOHAI UNIV
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